Apparatus for supplying ink to inking rollers



April 9, 1957 G. R. BRODIE APPARATUS FOR SUPPLYING INK TO INKING ROLLERSFiled Nov. 13, 1952 INVENTOR GEORGE/'1. BR 001 BY SJVL United State Pa eAPPARATUS FOR SUPPLYING INK TO INKING ROLLERS Application November 13,1952, Serial No. 320,264 2 Claims. (Cl. 101-350 The present inventionrelates to the art of printing and, more particularly, to an improvedmethod of supplying printing ink to an ink-transfer'roller. Theinvention is especially applicable to rotary printing presses andprovides an improved method of applying the ink and apparatus especiallyadapted to that purpose.

In the operation of conventional rotary printing presses, the ink issupplied to what is known as a fountain roller and is conveyed from thefountain roller by means of a so-called ductor to a series ofintermediate, parallel, ink-transfer rollers by which the ink isconveyed to and finally applied to the printing plates secured to theplate cylinder.

As is well understood in the art, the thickness of the film of ink onthe fountain roller is usually controlled by a so-called doctor blade.For practical reasons, also understood by the art, the peripheral speedof the fountain roller is relatively slow. The peripheral speed of theink-transfer rollers is usually the same as that of the plate cylinderand, in order to increase production, it is generally desirable thatthis speed be relatively high, substantially in excess of the peripheralspeed of the fountain roller.

By reason of this difference in vperipheral speeds of the ink-transferrollers and the fountain roller, it has been found impractical tooperate any of the ink-transfer rollers in constant peripheral contactwith the periphery of the fountain roller. In order to convey the inkfilm from the fountain roller to the series of 'inktransfer rollers, theso-called ductor has been employed.

The ductor is likewise a cylindrical roller positioned parallel to theother rollers of "the press and is adapted to be moved intermittently,first in contact with the surface of the fountain roller, from which itpicks up a film of ink, and then in contact with the first of the seriesof ink-transfer rollers, to which it appliesthe film. of ink picked upfrom the fountain roller.

While in contact with the fountain roller, the ductor tends to assumethe peripheral speed of the fountain roller and, when moved into contactwith the ink-transfer roller,'tends to assume the greater peripheralspeed of that roller. Thus, the peripheral speed of the ductor isconstantly changing and for the 'most part is either greater than, orless than, the speed of the roller with which it is brought in contact.Thiscondition has'caused an unevenness of the film of ink applied to theseries of ink-transfer rollers. It is also responsible for placingexcessive mechanical strains and stresses on the various elements of therotary press.

A further difiiculty encountered in rotary press operation is thefeeding-back into the ink fountain of any dried particles of ink orother solids, lint for instance, from the web, which might accumulate onthe series of ink-transfer rollers. Any such material will frequentlywork back along the series of rollers and be conveyed by the ductor tothe fountain roller which carries it back into the ink fountain.

It is an object of my present invention to eliminate ink-transferrollers and the fountain roller.

2,787,955 Patented Apr. 9,195?

the ductor and further to avoid all contact between the These and otherimportant advantages are derived from my present invention as willappear from the following description thereof. a

In accordance with my present invention, the printing ink is applied tothe ink-transfer rollers by means of a brush, co-extensive with saidrollers in length, rapidly rotating in close proximity to at least oneink-transfer roller, but out of contact with all ink-transfer rollers,aboutan axis parallel to the axis of' said rollers. At one or morepoints in the path of the brush, ink is applied to the bristles thereof.The-speed of rotation of the brush is such that, .atanother portion ofits path, the ink is thrown by centrifugal force onto one or more of theink-transfer rollers, v

The ink may be applied to the bristles of the rotating brush by movingthe bristles in contact with the surface of a conventional fountainroller, for instance, the amount of ink picked up by the bristlesdepending upon the thickness of the film of ink on the fountain rollerand being controlled by adjustment of the doctor blade in theconventional manner. However, the invention in its broader aspect is notrestricted to this particular method or means for applying the-ink tothe bristles of the rotating brush. Instead of using a fountain roller,other regulatory ink-carrying surfaces may be used to apply the ink tothe rotating brush. ,Such ink-carrying surface should be co-extensivewith the brush in length.

lnorder to avoid the throwing of the ink from the rotating brush ontoother parts of the press and press accessories, the periphery of thepath of the brush is, with advantage, substantially completelysurrounded by ink conveying surfaces, i. e., the ink-transfer rollersand the regulatory in-conveying surface by which the ink is applied tothe brush. However, other shielding devices may be employed for thispurpose, provided such shield be so constructed and arrangedasto preventthe accumulation of ink at points from which it might drip onto theink-transfer rollers and thus destroy the uniformity of the ink filmconveyed to the plate cylinder.

The invention will be morefully described and illustratedby referencetothefollowingdrawihgs of which Figure 1 represents, somewhatconventionally and fragmentarily, a vertical section of a rotary pressembodying the presently preferred aspect of the invention, and

Figure 2 is a fragmentary plan view of the rotating brush and fountainroller.

In the drawing, the supporting frame of the rotary press is indicated at1, the various rollers hereinafter described being supported by saidframe, as is well understood in the art. A conventional fountain rolleris indicated at 2 and the rollers 3, 4, 5, 6, 7, 8, and 9, representink-transfer rollers which, together with the fountain roller 2,substantially completely surround the peripheral path of the rotatingbrush represented at 10. Further ink transfer rollers 11, 12, 13, and 14serve to convey the film of ink from the roller 7 to the plate cylinder15.

The various rollers and the plate cylinder just described may be of theconventional type and, aside from the positioning of said rollers aboutthe rotating brush and the method of and means for supplying ink to therollers, the press may be of conventional construction and operatedaccording to conventional practices.

The rotating brush 10 comprises flexible members 16, advantageously ofbristles, or the like, cemented into or otherwise secured to blocks 17,advantageously of metal, the said flexible members and blocks beingcoextensive with the length of the rotating brush. The blocks 17 areprovided with longitudinal grooves 18, as shown, and are adapted to beremovably fastened, as by means of machine screws 19 and brackets 20, tothe main frame member 21 which, in turn, is keyed, or otherwise securelyfastened to, and adapted to be rotated with the shaft 22 which, inturn,is supported by the press frame 1; The brackets are provided at theirouter ends with lugs 23 which fit into the grooves of the respectiveblocks 17 and thus secure said blocks to the main frame of the rotatingbrush. Longitudinal movement of the blocks 17 is prevented by thefianges 24. The shaft 22 may be rotated by any suitable means, forinstance, a variable speed electric motor indicated at 25.

The brush construction illustrated has the advantage of ready removal ofthe bristle members for replacement or cleaning. However, other types ofrotary brushes may be used in place thereof without departing from thespirit of my present invention. For instance, I may use a cylindricalbrush having radially extending bristles uniformly spaced over theentire circumferential surface of the cylinder or over one or moresegments of the circumferential surface. In most instances, it will notbe found necessary, or desirable to have the bristles positioned aboutthe entire circumference of the cylinder, but they should, of course, beplaced substantially uniformly over the entire length of the brush.

In operation, a body of ink 26 is maintained in the ink fountain 27. Thefountain roller 2 is operated in a clockwise direction in contact withthe ink and the thickness of the film of ink carried from the fountainon the surface of the fountain roller is controlled, in the conventionalmanner, by the doctor blade indicated at 28.

The rotating brush 10, which is coextensive in length.

roller a distance such that when rotated, the bristles 16' move incontact with the constantly maintained film of ink of predeterminedthickness on the circumferential surface of the rotating fountainroller. Thus, the bristles of the rotating brush pick up a regulatedamount of ink from the fountain roller and this ink is thrown from thebristles by centrifugal force onto the surfaces of the surrounding inktransfer rollers. f

Advantageously, the speed of rotation of the brush roller is controlledindependently of the speed of the other rollers. The brush speed issubject to considerable variation, the optimum speed dependent uponother operating conditions, including the diameter of the path throughwhich the bristles rotate, the amount of ink required and the viscosityand tack of the ink. 'The optimum speed of rotation of the brush willusually fall within the range of about 60 to 600 R. P. M.

In the particular apparatus shown, the brush is indicated to rotate in acounter-clockwise direction. When so operated, the major portion of theink is usually thrown onto the surface of the ink-transfer rollerpositioned as represented in the drawing at 3. With this arrangement, auniform amount of ink is continuously supplied to the train ofink-transfer rollers, the amount of ink applied to the respectivelongitudinal sections of the rollers being nicely controlled byregulation of the doctor blade 28.

The rotating brush may be so positioned with respect to the fountainroller that the tips of the bristles barely touch the surface of theroller, or the brush may be pd sitioned closer to' the fountain rollerso that the bristles are somewhat flexed by contact with the roller. Inthe latter case, particles of ink may be thrown from the bristles ontothe cylinder 3 as the tension on the bristles is released upon passingout of contact with the surface of the fountain roller. It will appear,therefore, that the throwing of the ink from the bristles to theink-transfer rollers may not be entirely due to centrifugal force, butmay be effected, in part at least, by the flexing of the bristles.

The relative amount of ink applied to any longitudinal section of therespective ink-transfer rollers will depend upon the thickness of theink film on the corresponding section of the fountain roller and may bereadily controlled, as previously noted, by adjustment of the doctorblade.

I claim:

' 1. In combination with a rotary printing press comprising a pluralityof ink-transfer rollers, means for applying ink to the said rollerswhich comprises a brush coextensive with the length of the ink-transferrollers and adapted to be rotated in close proximity thereto, but out ofcontact with, said rollers about an axis parallel to the axis of saidrollers, a solid surface coextensive with the length of said brush andso positioned with respect thereto that, when the brush is rotated, thebristles thereof pass in contact with said surface, means for supplyinga film of ink to said surface and means for rotating said brush at aspeed such that the ink is thrown from the bristles onto at least oneroller, the solid surface and said ink-transfer rollers being sopositioned that the path of rotation of said brush is substantiallyentirely surrounded by said rollers and surface. a l

2. In combination with a rotary printing press comprising a' fountainroller and a plurality of ink-transfer rollers, means for transferringink from the fountain roller to the ink-transfer rollers which comprisesa brush coextensive with the length of the said rollers, and adapted tobe rotated in close proximity to, but out of contact with, said transferrollers about an axis parallel to the axis of said rollers, saidfountain roller being coextensive in length with the length of the brushand so positioned with respect thereto that when the brush is rotated,the bristles thereof pass in contact with the surface of the fountainroller, means for supplying a film of ink to the surface of the fountainroller and means for rotating said brush at a speed such that the ink isthrown from the bristles thereof onto at least one ink-transfer roller,the path of rotation of said brush being substantially entirelysurlrounded by the ink-transfer rollers and the fountain rol er.

References Cited in the file of this patent UNITED STATES PATENTSGermany -wuaaaasaaa. Nov.- 8, 1932

